1. Field of the Invention
The present invention relates to a FinFET (fin-shaped field-effect transistor), and more particularly to a FinFET having an epitaxial layer comprising a recessed and protruding profile, and a method of making the same.
2. Description of the Prior Art
In the rapidly advancing semiconductor manufacturing industry, FinFET devices are increasingly used in many applications and are integrated into various different types of semiconductor devices. The use of fins increases the surface areas of the channel and source/drain regions. This increased surface area results in faster, more reliable and better-controlled semiconductor transistor devices that consume less power.
As the size of the FinFET becomes smaller, however, the epitaxial layer serving as the source/drain region also shrinks. Therefore, the contact area between the contact plug and the epitaxial layer becomes smaller, which increases the sheet resistance of the contact plug.